Fix RPROperator blocking behavior

Author: Young-Leo

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/process/PatternRecognitionOperator.java

@@ -33,6 +33,7 @@
 import org.apache.iotdb.db.queryengine.plan.relational.planner.node.SkipToPosition;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.util.concurrent.ListenableFuture;
 import org.apache.tsfile.block.column.Column;
 import org.apache.tsfile.common.conf.TSFileDescriptor;
 import org.apache.tsfile.enums.TSDataType;
@@ -152,6 +153,11 @@ public OperatorContext getOperatorContext() {
     return operatorContext;
   }
 
+  @Override
+  public ListenableFuture<?> isBlocked() {
+    return child.isBlocked();
+  }
+
   @Override
   public TsBlock next() throws Exception {
     long startTime = System.nanoTime();